The Transport Layer Explained: How Data Moves Reliably Online

A diagram of the OSI Transport Layer showing data segments splitting into two paths: the reliable TCP path symbolized by a shield, and the fast UDP path symbolized by a lightning bolt.

In our last post, we saw how the Session Layer (Layer 5) establishes and manages the conversation between two applications. But once that conversation is open, how do we actually send the data back and forth reliably? That’s the crucial job of Layer 4: The Transport Layer. Think of the Transport Layer as the network’s […]